How much potential energy foes a 5kg mass have when its 2 meters above the ground?(Hint :PE=m*g*h)

Debris produced by mining is called

Consider two less-than-desirable options. in the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. in the second option you are driving 30 mph and crash head-on into a stationary brick wall. in neither case does your car bounce off the thing it hits, and the collision time is the same in both cases. which of these two situations would result in the greatest impact force?

Mixing salt in water is an example of physical change